1. Field of the Invention
This invention relates to apparatus for preventing flooding as a result of leakage from a water heater located in a building, and more particularly concerns apparatus for detecting such leakage and shutting off water flow to the leaking water heater.
2. Description of the Prior Art
Water heaters, whether in residential or commercial buildings, are susceptible to failure in a manner wherein the water within the heater and water entering the heater will leak uncontrollably onto the underlying floor. Such flooding could cause extensive damage to the building and its contents.
Systems have earlier been described for sensing a leak in a plumbing system, and automatically turning off the water feeding the plumbing system. One type of such detection and control system employs-flow monitoring sensors intended to discriminate between normal water flow and abnormal flows attributable to leaks. Such systems monitor either instantaneous flow or flows over a timed period, and send an electrical control signal to a shut-off valve. Such systems are disclosed, for example, in U.S. Pat. Nos. 4,589,435; 4,705,060; 5,000,224; 5,038,802; 5,056,554; 5,086,806 and elsewhere. Water shut-off systems of the aforesaid nature usually involve expensive computerized equipment and generally require specialized programming for proper installation.
In still other flood control systems, as disclosed in U.S. Pat. Nos. 4,324,268 and 5,240,022, sensors are disposed at floor level for detecting the presence of water, said sensors employing the water to complete an electrical circuit between two closely spaced electrodes. Such systems are unfortunately activated by the small amounts of water employed in the wet-mopping of floors, or small amounts of accidentally spilled water.
In yet another type of plumbing flood control system, a float-activated electrical switch positioned in a water-accumulating chamber is employed to control an electrically actuated valve. All the aforesaid plumbing flood control systems require a dependable source of electricity, and further permit the possibility of denial of water service to essential but sporadically operating systems such as fire extinguishing systems, lawn watering and cooling systems.
It is accordingly an object of the present invention to provide apparatus for automatically preventing flooding that might be produced by a faulty water heater.
It is a further object of this invention to provide apparatus as in the foregoing object which does not require a source of electricity.
It is another object of the present invention to provide apparatus of the aforesaid nature which is easily installable and is of durable construction amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.
The above and other beneficial objects and advantages are accomplished in accordance with the present invention by an apparatus for automatedly shutting off a water supply to a leaking water heater, said apparatus comprising:
a) a water-collecting tray having a perimeter sidewall and adapted to be positioned beneath said water heater,
b) an elongated rigid base strip attachable to said sidewall,
c) a shut-off valve secured to said base strip and equipped with an operating lever,
d) float means comprised of a buoyant head positioned within said tray, an elongated extension arm extending from said head to a distal extremity, a transverse arm extending orthogonally from said distal extremity and crossing over said sidewall, means for pivotally supporting said transverse arm, and a downwardly directed arm emergent from said transverse arm and terminating in a trigger extremity,
e) an elongated coil spring having a normally contracted state and having a first end attached to said strip at a site adjacent said buoyant head, and a second end directed toward said trigger extremity,
f) holding means for securing the second end of said spring when said spring is forcefully stretched toward said trigger extremity, said holding means being interactive with said trigger extremity in a manner to release said spring when said buoyant head is elevated by virtue of flotation upon water collected in said tray,
g) first tether means extending in engagement between the second end of said spring and the lever of said shut-off valve,
h) guide means secured to said strip for engaging said first tether in a manner causing said tether to have a sharply angled upward path directed toward said lever, and
i) second tether means attached to the second end of said spring and extending to a distal end having means to facilitate manual gripping for exerting pulling force to extend said spring from its contracted to stretched state, whereby
j) release of said stretched spring by said trigger extremity produces a pulling force upon said first tether means which moves said lever handle downwardly to a position representing closure of said shut-off valve.